Siemens SIMATIC S7-400H - System Status Change from the STOP System State; System Status Change from the Standalone Mode System Status

System and operating states of the S7–400H
11.2 System states of the S7–400H
S7-400H
126 System Manual, 03/2012, A5E00267695-11
11.2.3 System status change from the STOP system state
Requirement
You have selected one of the two CPUs in SIMATIC Manager and opened the "Operating
mode" dialog using the PLC > Operating state menu command.
Changing to redundant system mode (starting the fault-tolerant system)
1. Select the fault-tolerant system in the table.
2. Select the Restart button (warm restart).
Result:
The CPU displayed first in the table starts up as master CPU. Then the second CPU starts
up and will become the standby CPU after link-up and update operations.
Changing to standalone mode (starting only one CPU)
1. In the table, select the CPU you want to start up.
2. Select the
Restart (warm restart) button.
11.2.4 System status change from the standalone mode system status
Requirements:
● You have opened the "Operating state" dialog using the PLC > Operating state menu
command in SIMATIC Manager.
● The standby CPU is not in ERROR-SEARCH operating state.
Changing to redundant system state (starting the standby CPU)
1. In the table, select the CPU that is in STOP, or the fault-tolerant system.
2. Select the Restart button (warm restart).
Changing to system status STOP (stopping the running CPU)
1. In the table, select the CPU that is in RUN, or the fault-tolerant system.
2. Select the Stop button.